Core assembly for concrete molds



March 25, 1958 J. R. BENART ET AL 2,827,683

CORE ASSEMBLY FOR CONCRETE MOLDS Filed Sept. 20, 1955 5 Sheets-Sheet 1 INVENTORS J ua/m/ ,e. 55m i /G. 2 BY flflA/Ala A. BEA/A27 March 25, 1958 J. R. BENART ET AL CORE ASSEMBLY FOR CONCRETE MOLDS Filed Sept. 20, 1955 3 Sheets-Sheet 2 INVENTORS 14 /G. 4 Jfl/l/V ,2. gamer I BYDOA/AAD A. BEA/A27 March 1958 J. R. BENAR-T ET AL 7 2,827,683

CORE ASSEMBLY FOR CONCRETE MOLDS Filed Sept. 20, 1955 3 Sheets-Sheet 3 52 i K \\\\k\ Y 54 *4 IP 42' 4x I I I I 55 I 3a 4 /i l 2 I /50 F/G. 5 4 I 5 l/74 4 I 4 I 4 I /O' 4 I I I I 4 I /Z LII: 2:71: P 4-.- I 68 4 M 72 I I INVENTOR. I JOHN E. 6/VA.T

BY 00mm EEA/ABT CORE ASSEMBLY FQR CGNCRETE MOLDS John Richard Benart, Detroit, and Donald A. Benart, Farmington, Mich.

Application September 20, 1955, Serial No. 535,458

2 Claims. (Cl. 25-130) This invention relates to a core assembly for a concrete mold, and in particular has reference to the inside core of a mold, of the type used for precasting burial vaults, septic tanks, and the like.

Summarized briefly, the invention comprises an inside core assembly for a mold of the type referred to, so designed as to be operable either manually or by power, in such a manner as to contract the panels of the inside core assembly within the cast burial vault or other structure, after the concrete has set, so that the poured concrete casting can be removed easily and quickly.

Heretofore, difiiculty has persisted in removing a casting of the type referred to. Removal of the outside shell of the mold is a relatively simple matter, and presents no diificulties. However, the inside shell of the mold is difi'icult to contract, and requires an excessive expenditure of labor. The main object of the present invention is to provide a contractable inside core for a mold, that will swiftly contract, along both sides, at the ends, and at its top, responsive to actuation of a piston in a selected direction, thus to facilitate the removal of the previously poured concrete casting.

Another object of importance is to provide an inside core assembly as stated which will not only be capable of being contracted with ease, but further, will be capable of expansion with similar case, thus to prepare the mold for pouring of another casting.

Another object of importance is to provide a device as stated which will operate efliciently in every instance, both when being contracted or expanded, will be designed to cause all portions thereof that are in engagement with the inner surface of the molded casting to be drawn fully out of contact with said casting, will be relatively rugged, efiicient in operation, and so designed as to be usable with conventional outer shells of concrete molds.

Other objects will appear from the following description, the claims appended thereto, and from the annexed drawing, in which like reference characters designate like parts throughout the several views, and wherein:

Figure 1 is a perspective view of an inside core assembly for a concrete mold, formed according to the present invention;

Figure 2 is an enlarged longitudinal sectional view through the inside core assembly on line 22 of Figure 1, the dotted lines showing an outer shell associated therewith, the inside core assembly being expanded for pouring of the casting;

Figure 3 is a view similar to Figure 2 showing the core assembly in retracted position; v

Figure 4 is a plan sectional view on line 4-4 of Figure 2;

Figure 5 is an enlarged, detail sectional view on line 5-5 of Figure 3;

Figure 6 is an enlarged vertical sectional view on line 6"6 of Figure 4; and

Figure 7 is a still further enlarged, detail sectional viewon line 77 of Figure 3.

The inside core assembly constituting the present in- SEC vention has been generally designated at 10, and includes a base 12 of rectangular outer configuration, adapted to seat upon the mold base, which mold base will be discussed in greater detail hereinafter. The base 12 is in the form of an open, horizontally disposed rectangular frame, formed of angle metal material as shown in Figure 2, with an inverted L-shaped cross section.

Fixedly connected between the opposite sides of the base 12 is a transversely extending piston cylinder support member 14, in the form of a cross bar of inverted channel shape in cross section. Spaced equidistantly from the cross bar 14 at opposite sides thereof are end cross bars 16.

A pair of upstanding ears 17 are mounted upon the cross bar 14, medially between the opposite sides of the base 12. Ears 17 receive a horizontally disposed pivot pin aligned longitudinally with and extending above cross bar 14.

Pivotally connected at its lower ends to the pin carried by cars 17 is a cylinder 18, extending upwardly from the crossbar, and pivoting about the axis of the pin. Air under pressure is adapted to be directed into the cylinder, through hoses 19, 19, these being connected in communication with opposite ends of the cylinder, to direct air against opposite sides of a piston carrying a rod 20, projecting upwardly from the cylinder. When air is forced under pressure through the hose 19 shown at the right in Figure 2, the piston and its associated rod will be retracted within the cylinder, and conversely, the forcing,

of air under pressure through the other hose will extend the rod and piston to the position shown in Figure 2.

Secured to the upper end of the piston is a rectangular block 22 (Figure 4), and pivotally connected to the ends of the block, at opposite sides thereof, are pairs of links 24, 24, one pair extending in one direction from the block, that is, toward one end of the apparatus, and the other pair of links extending in an opposite direction. At their outer ends, the links are connected pivotally to elongated, inclined arms 26, pivotally attached at their lower ends to the bars 16 for swinging movement in a common vertical plane about axes extending transversely of the base adjacent opposite ends thereof, the pivotal connections of the arms to the bars being designated 28.

A cover plate has been designated at 30, and secured to the underside of said cover plate are U-shaped brackets 32, aligned longitudinally and centrally of the cover plate and shown to particular advantage in Figures 2 and 7. As shown in Figure 7, extending between the legs of each bracket 32 is a pin 34, adapted to be engaged in notches 36 of the arms 26 in the core contracting positions of the arms shown in Figure 3.

Relatively short draw links 38 (Figures 2 and 4) are provided, the draw links extending inwardly from the corners of the core assembly at approximately 45 degrees to the respective end and side walls of the assembly. The links at each end of the assembly are provided, at their inner ends, with a common pivotal connection 39 to the adjacent arm 26, and at their outer ends, have a universal connection 46, comprising vertical connecting pins extending through the outer ends of links 38, and received by ears projecting outwardly from horizontally extending sleeves 42'rotating upon horizontal pins 44 carried by' triangular corner plates 46 disposed in a substantially horizontal plane in the respective corners of the core assembly, adjacent the cover plate.

relation to the respective end and side walls of the device,

' and said side edges are provided with angular recesses 48,

shaped spacer bars 50 fixedly secured to the inner surfaces of the respective side and end walls and extending el h h h sid amend ells as sh wh ae 6 M1: i a I .l

Brojecting outwardly fromgthe triangnlar corner plates; 46,- at the intersection of their side-edges are tongues 52 fixedlysecured to wide, flat, spacer'bars54; The spacer bars- 54; along one side edge; thereof are, in engagement with adjacent side; edges of the end walls 5 6' of the, core assembly. I

Formed on said adjacent edgesof the-end walls 56 are inwardly projecting'flanges 58; there being flanges 58 similarly formed from the'side'walls ofthe coreassembly, the flanges at- -this corner of 'said assembly flaring; or; diverging in adirectioninwardly from the corners as shown in Figure" 5, so that in effect, the'sidewalls and end walls of thedevice have beveled edgesadjacent the cornets, with saidbeveled edges 'being spaced apart and, when the-core isinuse, with the spacer-bar 54 extending between the beveled edges in intimate contact therewith 'to provide a proper seal at the corners of the device. At each corner of thetdevice, an L-shaped rod- 60 is provided, the legs of each rod being extended perpendicularlyto one another, in parallel relation to the side and end walls of the device as shown in Figure 4. The rods 60 are disposed immediately above the respective cornerplates'46', and the legsoi the rods are slidable'in' sleeves 62 fixedly; secured to the upper endportions of themembers 50.

The spacer bars 54-are in such relationship relative'to' the angular rods 60 that, when the spacer bars 54' move inwardly from the positions thereof shown in Figure 4 to contract the core assembly, they'will engage the corner" portions'ofthe rods 60, andwill bias said rods inwardly, the rodsbeing shifted bodily along a path disposed at 45 degrees to the side and end walls. As a result, this exerts apull on the side and end walls or panels at their upper edge portion, tending to pull the same inwardly.

'To provide for preadjustment of the positions of the side and end panels in .the expanded condition of the core assembly, the ends of the rods are threaded, and are provided with adjusting and lock nuts 64 abut-ting against the sleeves 62 when the panels are swung outwardly, to t Referring now to Figure 6, at each corner of the base 7 12, there is. mounted a horizontally extending pivot pin 66, extending at an angle of 45' degrees to the respective side and end walls, and swingable on said pin is a sleeve 68," to, whichis secured a pin 70, projecting forwardly from the sleeve and extending through a small opening formed in the lower end of the associated spacer bar 54. free en of the pin 70' is. threaded to receive the nut 72 hearing against the spacer bar. 7 i l By reason of tbisan'angement, the spacer 'bar is pivotally mounted for swinging movement about a horizontal axis, with the, upper endrof' the spacer bar swinging inwardly or outwardly 'in a :plane disposed'at 45 degrees to p the planes .01 the side tendpanels. a I

The side panels have, been designated at 74, and are, like the end panels, pivotally mounted upon the base for swinging movement about horizontal axes extending along, thesides of the base. The hinge connections of the. side panels 74 to the base have been designated at 80, while thehinge connections; of lthetend panels '56 have been designated at82.. p

In use of the device, and assuming fol-example that the device has been in an expanded condition, with its side and. end. Panels (lying :in planes in closely spaced 7 Wallelrelationto the sides. andends of an outside mold shell, 78, there. willnbe Side andend spaces defined be tween th side. and end panels of the insides-core jiSSfinl: bly and of the adjacent walls of the outer rshelhtsaid spacesbeing designated at 84. 'Within thesespacesythe concrete is poured to provide a burial vault or similar structure, and said concrete is also poured over the cover plate 30. The spaces 84' are bottomed by the -base 12, as shown in Figure 2, and following casting of the burial vault or similar structure, and setting of the concrete, it

becomes necessary to remove the inside and outer cores or shells. Removal of the outer shell is not difficult, but heretofore, it has been difiicult to remove the inside 7, core assembly.

In accordance with the present invention, air is directed throughthe right hand hose shownin Figure 2, causing downward movement ofthe rod 20. This causes the rod 20 to move to the position shown in Figure 3, lowering t the block- 22- and exerting a pull upon the links 24. The

the side and end'panels of the core, engagethe. corners:

of the'rods 60, thus causing the side and end panels to be swung inwardly about their axes 8t), 32 in the mannerpreviously described; I V t Since the upper edges of the side and end panels and i also the upper ends ofthe' spacer bars 54, which were previously in conatct with the underside of the coverplate 30; have swung'through an arcuate path and have moved downwardly a slight extent as a result, the cover plate 30 is" free to be similarly moved downwardly, and

the'pins 34- or the bracket 32 become engaged, during the inward swinging movement of arms 26, with the notches 36, As the pins beginto move into the notches, the top edges 35 of the notches, at the outer ends thereof, willbear against the upper surface of thepins and willcama mingly bias-the same downwardly sufficiently to pnrmit the'pins to move freely into the notches. This win heo h served clearly from Figure 2, by noting that the outer ends of'the notches of arms26' travel'inarcs, when the arms-swing from their Figure 2 to their Figure 3fposi-1 tions, which arcs pass just below the upper'surfaces ofthe'pins. As a result, the cover plate is pulled downwardly and thustit will be seen that the side, end, and top' panels are all pulled-out of contact with the molded casting, permitting the casting togbe removed with a mini-j mum amountof difi'iculty.

When the inside core assembly is being extended to pe mit casting operati s; rt di e edi ro sh. the 19 showrrat 'theleft in Figure 2 to, extend the. piston a dZO-C T e arms 6 a e th s n utwardluand' amm h lyshs e heun e ide. o th erpanel "3.9, elevating the same. 7 At the same time, the outward moyementof thearnis, through the medium of links 378. and. P ate au e pa r ba s. 54V to, be swun ou wa d y,

21 8 7858 O f es nd EIJQBQQQB, exerting a ca acti n tsaidjfla ge l ih as the panels utwardly about he thingeax s to ert cal positl us-r Inthe fi a t of har' 4,..i is ensasedtight y bet een the. convergent:

edgesof'the flanges 58, to provide a seal, and the, con-t.

Q e e annnw be pou ed-V It maybe noted; inthis'. connection; h ta terhe ca e is fully expanded; e rodzl) con inues tormeve outwa dl rom theicy ind r, lforpethansaa ia ion 5m n h, fore it' istarrested at the endofthe stroke. This-chum. helinks let-to, be shifted; pastadea n e causing'a over center locking action, after which the core is. ready or t ephu ing .epera ions, At'thesame henh sideand endpanels are swung outwardly, the rods'60 are shifit dw thin associated sleeve 2. n i e l c nuts 64' bear against the ends of the sleeve A it believ dapnat nt that the invent nn s not ne inventionth: use: essaril y limit d tethe sp fic construction illustrated and described, since such construction is only intended to be illustrative of the principles, it being considered that the invention comprehends any minor change in construction that may be permitted within the scope of the appended claims.

What is claimed is:

1. An inside core assembly for concrete mold comprising: a fiat, horizontal, rectangular base: upstanding side and end panels spaced apart at the corners of the base and hingedly connected to the sides and ends of the base; a cover panel overlying the side and end panels and supported on said panels to be raised or lowered by swinging movement of the panels; spacer bars hingedly connected to the base at the several corners thereof and extending in the spaces between the side and end panels; means on the side and end panels engageable by the spacer bars when said spacer bars are swung inwardly of the base, adapted to impart corresponding inward swinging movement to the side and end panels, said spacer bars being adapted to bias the panels outwardly when swung in an opposite direction; and means on the base for swinging the spacer bars in opposite directions about their pivot axes, comprising a centrally disposed cylinder, a piston adapted for extension from and retraction into the cylinder responsive to the application of fluid under pressure to opposite ends of the cylinder, and a mechanical linkage connected between the piston and each of said spacer bars, said linkage including an arm pivotally connected to the base for swinging movement in a vertical plane, link means connected between said arm and the piston, corner plates attached to the respective spacer bars, and connecting arms pivotally connected between the corner plates and the respecitve arms, said first named arm adapted to engage the cover panel when swung in one direction to exert a downward pull on said cover panel.

2. An inside core assembly for concrete molds comprising: a base; a rectangular series of panels comprising a pair of side panels hinged to the base for swinging movement about parallel, horizontal first axes, and a pair of end panels hinged to the base for swinging move ment about horizontal second axes normal to the first axes; spacer bars operatively connected to the corners of the series and hinged to the base for swinging movement about horizontal third axes extending diagonally across the corners; means interposed between each bar and the side and end panels adjacent thereto, translating swinging movement of each bar about its axis into swinging movement of said adjacent side and end panels about their respective axes; means including an arm on the base connected with the several bars and swinging the bars simultaneously about their respective axes; a cover plate resting on the several panels, said cover plate being carnmed upwardly by the panels on swinging of the panels in one direction; and means on the arms and cover plate respectively, cammingly interengaging when the panels are being swung in an opposite direction, in an arrangement such as to bodily shift the cover plate verticaily downwardly within said assembly.

References Cited in the file of this patent UNITED STATES PATENTS 

